This invention relates to location-based devices and more particularly to a universal system for location reporting which transmits either synthesized voice or a digital representation of position over the voice channel.
As will be appreciated, in the past there have been numerous systems for reporting location to a dispatch operation from a wireless device, be it a handset or a fixed mount unit. As discussed in U.S. Pat. No. 4,833,477 issued to Robert K. Tendler, a system is provided for taking the output of a geolocation navigation unit, converting it into speech and transmitting the speech via wireless phone or other wireless communication device to a dispatch office or Public Safety Answering Point. Other patents involving location-based reporting are U.S. Pat. Nos. 5,193,215; 5,144.323; 5,555.286; 5,519,403; 5,414,432; 5,587,715; 5,557,254; 5,673,305 and 5,650,770. Central to most of the above location reporting systems is a change in infrastructure to permit the location reporting. For instance, in triangulation-based systems, a so-called head end system must be provided at each cell tower to provide the location information, which is then encoded in a specialized code and transmitted through the network to the dispatch office.
In addition, there are several GPS-assisted systems such as those offered by SnapTrack and IDC in which specialized communication channels are provided between the handset and the dispatch office.
The problem with all of the above systems is that they require additional infrastructure or additional invasion into the handset in order to provide location reporting from the handset to the ultimate recipient or dispatch office. Modifying handsets is indeed problematic because not only must the operation of the handset be altered in some manner in order to accommodate the location reporting, co-locating the GPS antenna with the handset-carried wireless antenna oftentimes causes interference problems. These interference problems start to exist when the GPS antenna is brought from a distance towards the wireless antenna, such that when the GPS antenna is within two inches of the wireless antenna interference starts to occur. Co-location of the GPS antenna and the wireless phone antenna, for instance at a spacing of one-quarter inch, results in measures which must be taken to eliminate the interference between the wireless phone and the GPS receiver.
There have been attempts in the past to link a GPS receiver to a wireless phone through a so-called hardwired umbilical cord which requires interconnection of the location reporting unit to the wireless phone unit within the wireless phone. While this type of system has been produced in the past, it does not result in a universally adaptable system without invasion into the wireless phone itself. As a result, wireless handsets need to be modified in order to provide the location reporting function.
Rather than hardwiring the location reporting unit to the wireless phone, in the subject invention an audio coupling is provided between the location reporting unit and the microphone normally utilized at the wireless handset. The information transmitted through the audio coupling, is in one embodiment, a synthesized speech rendition of the latitude and longitude developed as a result of decoding the output of a GPS receiver. This speech is coupled through the audio coupling to the microphone of the wireless handset and is then transmitted as over the voice channel to a dispatch office.
Additionally, in one embodiment, a DTMF tone generator is utilized in the location reporting unit to decode the output of the GPS receiver and to translate this output into DTMF tones, in embodiment in an ASCII II format, which is again impressed onto the voice channel by the audio coupling to the microphone, where it is then transmitted to the dispatch office in the normal manner that the voice channel is used for human transmitted speech.
What is accomplished is the provision of a locator module which is coupled to any wireless transmitter having a microphone through an audio coupling, with the location information being transmitted on the existing voice channel without either modification of the wireless transmitter or the network through which the communication is established. Thus, any wireless transmitter can be adapted to be a location reporting devise without modification. Moreover, the network over which the location reporting is transmitted need not be modified in any way.
While the subject device will be described in connection with wireless handsets, it will be appreciated that any wireless communication device having a microphone is within the scope of this invention. Thus, the subject locator module may be utilized in connection with SSB radios, VHF radios, CB radios, family radios and with those satellite communication systems which support voice channels.
In one embodiment, the audio coupling is through the utilization of a coupler which may be placed over the microphone carried by the handset, with the attachment to the handset either being via suction, adhesive attachment or mechanical attachment.
In another embodiment, the locator module may be configured to house the wireless phone so as to perform a cradle-like function in which the handset is attached to the cradle, with the cradle providing an acoustic coupling between itself and the microphone of the handset. In this embodiment, the GPS receiver, the GPS antenna, the location board and the optional battery may be contained within the cradle, with the phone being able to report location when it is in the cradle.
What is therefore accomplished is that rather than utilizing complicated signaling systems such as packet data, modems, and other proprietary signaling systems for the reporting of location information, a simplified system is provided in which no modifications whatsoever need to be made to the handset, much less any other type of wireless communication device. The only requirement is that there be an audio coupling between the output of either a speech synthesizer or a DTMF generator, or both, to the microphone of the wireless device. This makes the adaptation of any wireless device a location reporting device with no incursion into the device itself.
Thus the more than 60 million cell phones presently in operation in the United States may be adapted to location reporting phones by the mere provision of the audio coupling and the locator module.
In one embodiment, the locator module includes an integrally carried GPS antenna, whereas in another embodiment the GPS antenna is separate from the locator module. Moreover in the preferred embodiment, the locator module has an internal battery for powering the GPS receiver and antenna as well as the location reporting unit, which includes a speech synthesizer, DTMF tone generator and audio amplifier. Alternatively, external power may be provided to the locator module such that if the locator module is utilized as a handset cradle in a vehicle, the power for the unit may come from the vehicle battery itself.
It will be appreciated that not only is latitude and longitude reportable by virtue of the subject audio coupling, any other messages which are either in synthesized voice or DTMF tone coding can be provided in this manner. This means that not only can location be transmitted, but also the telephone number or mobile identification number of the wireless phone, the license tag number of the vehicle, the time since last fix if a GPS receiver is utilized, and indeed any other type of information which is generated outside of the handset.
It is only important that the signaling be done over the voice channel as such and as part of the subject invention DTMF tones may be transmitted over the voice channel to report position.
Moreover, while GPS location receivers are described herein, any location reporting apparatus is within the scope of this invention as long as the location coordinates can be translated into either speech or DTMF coding. Moreover, it is not necessary that DTMF coding be the only coding utilized. Any coding which results in audio signals to be transmitted over the wireless voice channel is within the scope of this invention.
In summary, an audio coupling is provided between a location reporting unit and the microphone of a wireless phone in which location information is provided either by synthesized voice and/or DTMF tones through the audio coupling to the microphone such that the location of the wireless phone can be broadcast on the normal voice channel to a dispatch operation such as a Public Safety Answering Point or to a location-based service provider. The subject interface makes possible the adaptation of any wireless phone to provide location-based information without change to the wireless phone and without any additional infrastructure for the wireless network. The utilization of synthesized speech and/or DTMF tones over the voice channel provides a universality for the system, which can be utilized anywhere where there is both wireless and GPS satellite coverage.